FIFA 21 - What Am I Doing Wrong?

[Fridge Combat]

Hi everyone!
Firstly, apologies for the vague title and long post, but I'm at my wits end trying to figure out why I'm finding this game so difficult. I've watched a bunch of tutorial videos but none have been particularly helpful, I just really enjoy this game but want to be competitive!

So some context: I'm currently playing a league 2 team on Legendary difficulty. I heard World Class was actually harder due to lack of defending, so I settled where I am. I've input Matt10's popular slider set also.
On Professional difficulty I am beating teams like Liverpool 10-0 in the FA Cup tournament, but on this difficulty I'm losing 3-1 to teams like Mansfield.

I have experience with Madden so I'm familiar with most of the fundamentals of defense so my jockeying and player/swap is pretty good, yet they always find a way through. I can score, on average, a goal a game, but my players are constantly dispossessed or tackled with no fouls called.

For clarity, I have been through and changed my formation to best suit my available players and retrained those I need to. I've set instructions in all my schemes (though I don't know if they're correct), but I'm not positive if I'm using them in the right situations.

Basically I'm looking for any advice that would help me be more competitive against the AI whilst still providing a challenge. I don't mind losing, in fact I'd rather not win every game, I just hate feeling like I'm either getting ****ed over or don't have the skill set required.

Thank you so much in advance!

[piffbernd]

Adjust the sliders an tick maybe by 2 up or down. Use an team that uses the same formation. When I win against bottom teams and u have an challenge against the top 6 u should be there. I played with Bristol Rovers and the defenders are terrible.